This Day Aria
by crazyguitargirl
Summary: One-shot songfic. Mabel's wedding day is in put jeopardy when she finds herself and Dipper stuck in the mines under Piedmont. Will she be able to escape in time to stop the evil scheme that is unfolding? I own nothing.


**Hi guys. Out of boredom I wrote a Gravity Falls version of This Day Aria, because I realized how likely (and cool) a changeling invasion would be in Gravity Falls. I do not own the song, but I highly recommend you listen to it on Youtube.**

Dipper Pines blinked, still in shock by what had just happened.

_How could Mabel turn on me? How could she do that on a day like this?_

The Piedmont mines bore little to no light at all, yet still the recent college graduate felt the need to escape. With the dim light provided by a flickering lantern, he could see a wall of small rocks. With all the strength he still possessed, Dipper flung himself at the wall. The top half of it crumbled to the ground, revealing a dark tunnel.

Suddenly motivated, the brown haired boy started to run towards through the open tunnel, quickly stopped by a soft figure on the ground.

Her hair was undone. Her face was covered in streaks of dirt, and her clothes were wrinkled and torn as if she hasn't changed in weeks, but it was undeniably Mabel.

The Mabel who had trapped him.

The Mabel who had betrayed him.

Dipper raised his arm, preparing strike her, when Mabel's brown eyes grew big and her arms were thrown up to her face for protection.

"No! Please!" She looked up, and the fear in her eyes melted to give way for relief. "Dipper! Oh, I'm so glad you found me. We have to get out of here-"

"Who are you?" He yelled, his voice bouncing off of the walls of the chasm. "Who are you really?"

"It's me!" She claimed. "Mabel!"

"Likely story." He sneered, once again preparing to hit her.

"Wait!" Dipper could only watch in surprise as the girl stood and began to recite a familiar nursery rhyme.

"Well, who wants a lamby, lamby, lamby? I do! I do! So go up and greet your ma'amy ma'amy ma'amy. Hi there! Hi there! March, march, march around the daisies, don't-don't-don't you forget about the babies!

"M...Mabel?"

The older twin's eyes glistened as she embraced her brother in a hug.

"I'm so happy you're here." She whispered. "I've missed you."

"How did you get here?" The boy pulled back. "What's going on?"

"I'll explain all of that later." Mabel promised. "But we need to find a way out of here. Anthony, and possibly the whole town, is in jeopardy."

-.-.-.-.-

"Mabel, you look gorgeous!" A bridesmaid squealed with delight.

The bride spun around in front of the mirror, her floor-length gown swishing on the marble floor. Her expression never faltered from bored and uninterested as her closest friends helped her get ready for her special day.

"Yes, I suppose so," she said, her voice dripping with nonchalant.

"You're a very lucky girl!" Her Chinese friend commented. "The town's best police officer- you two were in love the moment you met!"

"Yes, yes." The fake muttered. "My groom. Could I please have a moment alone?"

"Of course." Grenda ushered the other two out of the hotel's suite. "We're so proud of you, Mabel. We hope you have a great time."

The moment the door shut, Mabel turned to the vanity mirror, sitting in the plush chair. Her brown eyes glowed bright green as a wicked grin crossed her face. She let out an evil laugh which echoed in the spacious room.

The imposter plucked a single red rose from one of the vases sitting atop the table. Dozens of them had arrived on the grooms request. The real bride must have been awfully fond of them.

"_This day is going to be perfect_," she sang happily while placing the bloom in her intricately-pinned-up hair. She spun around, her dress flying behind her before she stopped to admire her smoothly manicured hands.

They were far from what she usually possessed.

"_The kind of day of which I've dreamed since I was small..."_

Mannequins clad in bridesmaid dresses flanked her in a perfect circle. The disguised girl curtsied with mock happiness, singing dreamily, "_Everybody will gather round, see I look lovely in my gown..."_

Abruptly, she knocked one down, her eyes once again glowing a sickly shade of chartreuse. She pronounced, "_What they don't know is that I have fooled them all!"_

Meanwhile, Dipper and Mabel continued their struggle to exit the caves and stop the wedding before it was too late.

Mabel ran down a dimly lit tunnel, tears springing to her eyes driving her to sing, "_This day was going to be perfect, the kind of day of which I've dreamed since I was small..."_

She sat, staring at her own reflection in a rusted cart. She was scraped, bruised, and covered in dust, the hopeful gleam lost from her eyes.

"_But instead of having cake, with all my friends to celebrate..._"

Dipper leaned down, trying to comfort his twin. She glanced at him, her eyes suggesting that it wasn't the time.

"_...my wedding bells, they may not ring for me at all..."_

Upstairs, the imposter ran her hands down the smooth satin of her gown, stating, "_I could care less about the dress..._"

An innocent basket of apples was shoved off of a table with "_I won't partake in any cake!"_

She caressed a mannequin sporting a tuxedo and a green hat, closing her eyes and maniacally singing, "_Vows? Well, I'll be lying when I say..." _

Her voice filled with disgust as she mocked what she was to say; "_That through any kind of weather, I'll want us to be together..."_

She noticed the hat, feeling that it wasn't fitting. After all, this day must be perfect.

_"...the truth is, I don't care for him at all!"_

The hat was thrust into the air, shortly hitting the ceiling before coming back down, crushed.

"_No, I do not love the groom!"_

The room became a blur as she spun around, casting an eerie shadow on the ceiling.

"_In my heart, there is no room!"_

Mabel's imposter banged her fists on the table, causing a vase to clatter and fall.

"_But I still want him to be all mine!"_

The real Mabel Pines was growing more and more desperate for escape, her brother aiding her as she ran. They both knew they didn't have much time left.

"_Must escape before it's too late, find a way to save the day!"_

Dipper wanted more than anything to help his sister, but he was for once without a plan.

Seeing her brother's loss in hope, she assured him, "_I know I'll be lying if I say, 'I don't fear that I may lose him to one who wants to use him; not care for, love, and cherish him each day!'"_

The twins skidded to a halt in front of an abandoned cart and train tracks that spiraled down for seemingly miles.

Mabel broke down. She fell to her knees trying to push the cart, crystalline tears streaming down her dirty cheeks.

"_For I oh-so love the groom, all my thoughts he does consume..."_

Dipper smiles, remembering how passionate his sister used to get when she fell in love as a young teen. His drive was renewed, and he ran to help his sister with the cart. It had several rocks stuck inside of it that he struggled to dislodge, but he managed to pull them out. The cart began to roll forwards, and they both ran in.

"_My knight in shining armor,"_ she called as they flew down the down the tracks, "_I'll be there very soon!"_

Everything seemed to be going great, until the tracks ended abruptly and the twins were thrown out of the cart. It felt like everything was over, but Dipper managed to grab the edge of a cliff, cutting his hand in the process, and pull the both of them scrambling to their feet.

The doors to the chapel above ground swung open as Mabel made her grand entrance, stepping on the white rose petals that the flower girls had dropped when they had graced the aisles.

"_Finally, the moment has arrived_," she sang triumphantly, but under her breath as she smiled at the rows of guests. "_For me, to be one lucky bride!"_

The imposter joined Anthony, the groom, on the steps, facing him.

She gave a small grin when she saw the weakened dimness of his eyes.

Everything was working.

The twins leaped across the cavern before Mabel stopped altogether to state, "_Oh, the wedding we won't make, he'll end up marrying a fake! My shining armor will be..._"

The fake grinned.

"Mine. All mine!"


End file.
